Role of Orai‐family channels in the activation and regulation of transcriptional activity

Store operated Ca2+ entry (SOCE) is a cornerstone for the maintenance of intracellular Ca2+ homeostasis and the regulation of a variety of cellular functions. SOCE is mediated by STIM and Orai proteins following the activation of inositol 1,4,5‐trisphosphate receptors. Then, a reduction of the endoplasmic reticulum intraluminal Ca2+ concentration is sensed by STIM proteins, which undergo a conformational change and activate plasma membrane Ca2+ channels comprised by Orai proteins. STIM1/Orai‐mediated Ca2+ signals are finely regulated and modulate the activity of different transcription factors, including certain isoforms of the nuclear factor of activated T‐cells, the cAMP‐response element binding protein, the nuclear factor κ‐light chain‐enhancer of activated B cells, c‐fos, and c‐myc. These transcription factors associate SOCE with a plethora of signaling events and cellular functions. Here we provide an overview of the current knowledge about the role of Orai channels in the regulation of transcription factors through Ca2+‐dependent signaling pathways.